Carts that can be put on board on a transport vehicle such as a motor truck, able to be used in the loading and in the unloading of the motor truck and then to be attached to the rear of the latter to thus be transported, are known. This type of cart is generally of compact production so as to project beyond the motor truck by a small distance, its chassis being made so that the wheels are close to the front end of its loading fork.
For this purpose, the motorized trucks of the above-mentioned type generally comprise a chassis that is shaped like a forward-facing U, equipped with two front steered wheels and one rear steered wheel, so that the lifting means thus extend into their most retracted position between the lateral branches of the U-shaped chassis.
Certain trucks of the above-mentioned type comprise at least three steered wheels so as to allow handling in frontal mode and in lateral mode.
Each steered wheel is mounted on a direction mechanism with pivoting around a vertical axis between a first frontal mode position and a second lateral mode position that is perpendicular to the first position of the frontal mode.
The invention is particularly useful in its application to a motorized truck, able to be put on board at the rear of a transport vehicle, of the type that comprises a chassis that has a U-shaped conformation, equipped with two front steered wheels and one rear steered wheel, a control station and lifting means. These lifting means can comprise a telescopic arm that is mounted to pivot under the action of a lifting jack around an essentially horizontal axis that is located to the rear of the chassis essentially above said rear steered wheel or alternately can comprise a lifting mast of the type that is known in the art.
A first drawback of this on-board truck with three steered wheels results from the fact that in the lateral travel mode, the deformation and the reduction of the polygon or lifting triangle entrains a reduction in stability.
A second drawback of this on-board truck with three steered wheels derives from the risk of the load interfering with the front wheels in the lateral travel position, which may prevent the deposition of the load between the front wheels.
The document EP 0 625 478 A1 describes a cart with movable forks according to the above.